Preparations Of Several Carbon Nanofilm Electrodes And Their Application In 4-Nitrophenol Electroanalysis

Carbon nanomaterials with excellent electrical conductivity,rich surface functional groups,high specific surface area and good adsorption performance are widely applied in many aspects,such as catalysis,optics,and analysis.Therefore,it is important to explore some novel,simple,mild,cheap and controllable preparation methods of functional carbon nanomaterials.In this thesis,carbon nanofilms were prepared with smooth carbon substrate by electrochemical method and applied to the electroanalysis of 4-nitrophenol?4-NP?.The main contents are as follows:1.A graphene oxide?GO?film electrode was facilely constructed for sensitive determination of 4-NP.The film electrode was fabricated by anodic oxidation of a smooth pencil electrode in a blank H₂SO₄electrolyte and then ultrasonic irradiation in N,N-Dimethylformamide?DMF?.The pencil electrooxidation resulted in the increase of oxygen-containing functional groups and the expansion of the interlayer distance of graphite.Then,the GO film formed after the ultrasonic treatment of oxidized pencil in DMF.The resulting film electrode showed excellent electrochemical performances toward 4-NP reduction.The film electrode was used to sense 4-NP with a wide linear range of 10 nM to 60?M,a very low detection limit of 6 nM.The present method exhibited several advantages of easy to control,mild conditions,free decoration,high sensitivity and selectivity,and satisfactory quantification of 4-NP concentration in real water.2.The multi walled carbon nanotubes/graphene oxide?MWCNTs/GO?film electrode was synthesized by ultrasonic irradiation of anodized pencil in DMF solution containing MWCNTs for several seconds.The prepared film electrode showed excellent performances in sensing 4-NP with a wide linear range of 10 nM to 20?M,a very low detection limit of 5 nM.The sensor was successfully used for the determination of 4-NP in real water samples with satisfactory results.3.A highly sensitive electrochemical sensor for 4-NP was facilely constructed based on a Nafion modified glass carbon nanofilm electrode?Nafion-GCNFE?.The GCNFE with high activity was quickly fabricated from a smooth GC surface in a blank electrolyte solution of H₂SO₄ with square wave potential pulses?SWPPs?,this uniform film was rough surface and decorated with oxygen-containing functional groups,where the nanofilm formation might be related to repeated anodic oxidation coupled with SO₄^2-intercalation/deintercalation.Under an optimized detection condition,the electrochemical sensor based on Nafion-GCNFE exhibited excellent performances in sensing 4-NP with a wide linear range of 10 nM to 50?M,a very low detection limit of 4 nM?3?/slope?,easy fabrication,good reproducibility and reusability,high selectivity and long-term stability,which was successfully used for the 4-NP determination in real water samples with satisfied results.